Four-stroke MotoGP boom comes to historic Assen.

Four-stroke GP bikes return to Assen this weekend for the first time in almost three decades, with Honda's rampant RCV riders Valentino Rossi (Repsol Honda Team RCV211V) and Tohru Ukawa (Repsol Honda Team RCV211V) leading the charge.

The HRC duo have totally dominated the early stages of the sport's new four-stroke era, winning all six races so far, and this Saturday they aim to give Honda its first four-stroke Dutch TT win since Mike Hailwood won the 1967 500 race on his RC181. Rossi's and Ukawa's current form suggests that they will continue to reign supreme at historic Assen, the only circuit remaining from motorcycling's inaugural World Championship year in 1949, but the track's unique layout and the region's changeable summer weather make the outcome difficult to predict. The heavily cambered Assen track has also undergone several revisions for 2002, adding another element of surprise to the proceedings.

Rossi was in the hunt for 500 victory at Assen 2000 and 2001 but rain intervened on both occasions, leaving the Italian sixth and second. This weekend, when the MotoGP race will commence 90 minutes later than usual to accommodate the World Cup third-place playoff, the Italian youngster will therefore bid for his first premier-class win at bike racing's most historic venue.

"I've never won the big race at Assen, so I hope we have some good weather this time," says Rossi, who won his first-ever 250 GP at Assen in 1998, 12 months after winning the 125 race. "Assen is a great track, and the most difficult because it's impossible to make two laps exactly the same. I think it will be hard work on the four-stroke, because I don't know if it'll be possible to use all the RCV's power. Already with the 500 you couldn't use 100 per cent of the power. Assen is very strange and very difficult because you never go straight, you never have one second to say 'Ah, a straight, so now I can rest'. For sure we should be faster than the 500s, but only if we can use all of the four-stroke's power."

Ukawa is the only man so far this year to have defeated Rossi (he beat his team-mate by a fraction of a second in April's South African GP) and another victory would be the perfect way for him to celebrate his 100th GP start. The Japanese rider knows how to win at Assen - two years ago he won the Dutch 250 TT - but last year he found his first 500 race at the track a more difficult experience. Ukawa qualified 11th and finished eighth, finding the complex venue an altogether different kind of a challenge on a much faster motorcycle.

"The RCV will be very interesting at Assen!" Ukawa smiles. "The 500 was very difficult around there, because the bike was almost flying off the camber! But although the four-stroke is even faster, I think it might be easier to use, because the power delivery is more smooth and because the bike is more stable than the 500. We will have to work very hard at set-up because Assen places very unusual demands on the chassis and suspension, but so far this year we've found that the bike works well everywhere. We are fast almost immediately, even when we've never used the RCV at a track before. But Assen is very different, so we won't really know what's going to happen until we get there."

Honda's five NSR500 two-stroke riders hope that the RCV will be more within their reach than usual at Assen, and there's a theory on pit lane that the 500s might have one of their best weekends of the year at the high-speed Dutch track. The two-strokes lose most against the new and super powerful four-strokes during acceleration, but since Assen is an ultra-fast circuit with fast corners and long straights, acceleration isn't of prime importance in the big class.

"It's difficult to predict how Assen will be for us," says Loris Capirossi (West Honda Pons NSR500), who started last year's Dutch TT from pole position, finishing the race a close-run third. "Some people say the 500s will be competitive there, but I'm not so sure, I think we won't really know until we've completed the first couple of sessions on Thursday."

Team-mate Alex Barros (West Honda Pons NSR500), who made his 200th Grand Prix start at the Catalan GP two weeks ago, is also unsure of what awaits him this weekend. "I'm quite confident of a good weekend, because the last two races have gone really well for me," says the Brazilian, who won the 2000 Dutch TT on an NSR500 and was top two-stroke rider at Catalunya. "But I'm not sure how we will compare to the four-strokes at Assen. So far this year we've not been able to get close to the quickest four-strokes. Maybe Assen will be different, maybe it won't."

The pair's technical director Antonio Cobas reckons that Capirossi and Barros can look forward to good results. "I think we a good chance of matching the four-strokes at Assen because there are no slow corners followed by a long straight, which is the worst situation for us," he says. "Both Loris and Alex have always done well at this circuit because it's got so many fast corners."

Like Ukawa last year, reigning 250 World Champion Daijiro Kato (Fortuna Honda Gresini NSR500) faces a major challenge at Assen - his first big-bike race at the track. Kato ruled 250 racing last season but poor weather spoiled his hopes of victory in the Netherlands, and he must look at this visit to the Dutch venue as a learning weekend. Back on track at Catalunya, after tumbles in France and Italy, Kato is looking forward to continuing a return to his impressive earlier form. "After two difficult races, Catalunya proved that we can perform well," says Kato. "I know Assen will be a big challenge for me, but I'm ready for that. The track probably takes more time to learn than others, so my plan is to get in as many laps as possible during practice and qualifying. For that reason especially, I hope the weather stays dry for all three days."

Jurgen van den Goorbergh (Kanemoto Racing Honda NSR500) ended an impressive run of points-scoring runs at Catalunya where he was knocked down by a rival on the very first lap. The Dutch hero will be hoping for a better race at home. "The last race was quite difficult in all kinds of ways, and I think we can look forward to something much better at Assen," says van den Goorbergh, darling of the Dutch crowd for the last few years. "Everyone knows we are in a development phase at the moment, developing MotoGP tyres for Bridgestone. This means we aren't just racing, we're also testing and evaluating, but I think we've done well so far, scoring points at four races and giving Bridgestone a huge amount of feedback. They're working incredibly hard and keep offering us new tyres. Assen is very unusual from a tyre point of view but I think we'll have a good race if we go okay in practice. Of course, I want to put on a bit of a show for the crowd, so I'll be doing my best to get as close to the front as I can."

Fifth NSR rider Tetsuya Harada (Pramac Honda NSR500), who has shown some promising flashes of speed at the last few GPs, is another man who knows all about the unique challenges offered by Assen. "I've won on the 250 there but it's a very different racetrack on a 500," says the Japanese. "Some of the bits that are straight on a 250 become corners on the 500, so you have to learn your lines all over again. The NSR will be the quickest bike I've ever raced there, so I expect to be learning and thinking a lot through the weekend!"

In the 250s, Robby Rolfo (Fortuna Honda Gresini NSR250) will be trying everything in his power to go one better than his Catalunya result. The Italian youngster, who scored his second runner-up finish of the year at the Spanish track, needs a good result on Saturday to keep title rivals Fonsi Nieto (Aprilia) and Marco Melandri (Aprilia) in sight. "Assen will be tough for us because we still lack a little acceleration and it's a fast track," says Rolfo. "But we proved at Catalunya that we can do okay at fast circuits, so we'll be trying everything to keep fighting for our first win. I think we improve with every race, so Assen could be good for us, though I think the next two races at Donington and Sachsenring will be even better."

Team-mate Emilio Alzamora (Fortuna Honda Gresini NSR250), who had an unlucky GP at Catalunya, hopes for better at Assen, where last year he scored his best-ever 250 result, taking second in a tricky wet and dry 250 race. "Another podium would be great, especially at Assen which everyone knows is a real riders' track," says the Spaniard. "We will do everything we can to close the gap on the front guys. The bike is good, but you need a lot of speed at Assen, and that's probably the one area in which we lack at the moment."

Teen 125 genius Daniel Pedrosa (Telefonica Movistar Jr Team Honda RS125R) continues his hunt for his first GP win this weekend, after scoring his best-ever result at Catalunya. Pedrosa came within two hundredths of a second of his first world-level success at his home track and should be in the hunt for victory once again at Assen.

"I was very close at Catalunya, but second place is always second place, however close you are to the winner," says Pedrosa, currently third in the 125 World Championship. "I'll be trying my hardest to go one better at Assen, though I know it'll be difficult because we do need a bit more straight-line speed. Last year I qualified tenth, which I was happy with, but I didn't finish the race. I've a lot more experience now, so I hope for a better weekend.

After Saturday's Dutch TT the GP circus crosses the English Channel for the British GP on July 14, midpoint in the 16-event 2002 GP season. The action continues the following weekend at the Sachsenring in Germany, which precedes the sport's traditional month-long summer recess.